1. Field of the Invention
This invention relates to a power supply structure in a sliding structure which is applied to a slide door of a motor vehicle, and can absorb the looseness of a wire harness with opening/closing of the slide door in order to supply power from e.g. a vehicle body (power source) to the slide door all the time.
2. Description of the Related Art
The slide door of e.g. one-box car is provided with functional components such as various electric appliances (e.g. a power window motor, a switch unit for operating a motor and a window scissoring preventing sensor) and an auxiliary component.
In order to supply these functional components with a power and signal current, a wire harness is wired from a vehicle body (battery side) to a slide door, and connected to each of the functional components within the slide door. Power supply to the respective functional components must be done regardless with the opening/closing state of the slide door.
However, in order to make charging all the time, the wire harness on the side of the slide door must be caused to expand or contract to absorb the opening/closing stroke with the opening/closing operation of the slide door or sliding structure (looseness absorbing mechanism). To this end, various components such as a guide rail, slider and an arm member are required. This gave rise to various problems of an increase in the number of components, complication, high cost and upsizing of the structure and an increase in the weight of the slide door.
Where such a looseness absorbing mechanism is not provided, when the slide door is opened or closed, the wire harness sags or looses so that it is caught into between the slide door and a vehicle body. In addition, it may vibrate owing to vibration while a vehicle runs so that it is damaged owing to its interference with other components.
Even where the looseness absorbing mechanism is used, if the slide door is opened or closed in a greater degree than a prescribed opening/closing stroke, excessive tension may be applied to the wire harness, and hence undue stress may be applied to the respective wires of the wire harness. Where the wire harness with relatively long wires has been manufactured, the wire harness (electric wires) may be caught into between the slide door and the vehicle body when the slide door is opened or closed. On the other hand, where the wire harness with relatively short wires has been manufactured, excessive tension may be applied to the wires when the side door is opened or closed, and hence undue stress may be applied likewise.
An object of this invention is to provide a power supply structure in a sliding structure with a simple, inexpensive and small structure which can surely absorb the looseness of a wire harness when the slide structure is opened or closed and prevent an excessive tension from being applied to the wire harness, the wire harness from being caught into between itself and a vehicle body and the wire harness from interfering with other components owing to vibration.
In order to attain the above object, in accordance with this invention, there is provided a power supply structure in a sliding structure comprising:
a wire harness a first end of which is secured to one of a sliding structure and a body and a second end of which is connected to the other of the sliding structure and the body, the wire harness being arranged between the sliding structure and the body; and
an elastic member arranged along the wire harness in a longitudinal direction of the wire harness from the first end of the wire harness so that wire harness is supported by the elastic member.
In this configuration, even if the wire harness is pulled when the sliding structure is closed, the wire harness is supported in the curved state by the elastic member. In this case, the curved portion of the wire harness is extended against urging by the elastic member so that the pulling force is absorbed, and not tightened. Thus, the wire harness does not suffer from undue stress, which prevents the wire harness from being damaged. Since the wire harness is urged always in a pulling direction by the elastic member, it does not have looseness. Therefore, it does occur that the wire harness is damaged owing to interference with other components owing to e.g. vibration.
The pulling force of the wire harness is relaxed as the sliding structure is opened. However, simultaneously, the elastic member urges the wire harness in the pulling direction so that the looseness of the wire harness is absorbed. This prevents the wire harness from being caught in between the sliding structure and the body. Further, since the looseness of the wire harness can be absorbed by a simple structure using only the elastic member, the component cost and assembling cost is low and an increase in the weight of the sliding structure can be suppressed.
Preferably, the elastic member is secured to the wire harness. In this configuration, since the wire harness and the elastic member are integrated, the wire harness neither deviates from the elastic member nor floats therefrom. When the wire harness is pulled and contracted, the elastic member surely follows the wire harness to urge the wire harness in a direction of suppressing the looseness. Thus, the looseness of the wire harness can surely be absorbed. Previous assembling of the wire harness with the wire harness can facilitate the assembling of the wire harness with a motor vehicle.
Preferably, the elastic member is a lengthy flat spring. In this case, since the elastic member is simple in shape, the material cost and production cost of the elastic member are low. The lengthy flat spring can be easily secured along and to the wire harness. Further, since the lengthy elastic member is in contact with the wire harness in face or linear contact over the entire length, the urging force is uniformly acted on the wire harness. Therefore, the bending operation of the wire harness when it is pulled and the operation of absorbing the looseness when it is contacted can be done smoothly and surely. This prevents the wire harness from suffering from undue stress.
Preferably, a stem of the elastic member is located at a fixed side of the wire harness whereas a tip of the elastic member is located at a top of a curved segment of the wire harness. In such a configuration of the elastic member, since the one end of the elastic member is located on the fixed side of the wire harness, the elastic member makes smooth bending at a fulcrum of the fixed side of the wire harness. This permits the looseness of the wire harness from being surely absorbed. Further, the other end of the elastic member is located at the top of the curved portion of the wire harness, the clear arc shape of the curved portion of the wire harness is assured when the sliding structure is opened/closed. This prevents the wire harness from being bent unduly, and prevents the wire harness from suffering from undue stress.
Preferably, the elastic member is arranged along a curved inner face of the wire harness. In this case, since the elastic member is located not along the curved outer face but along the curved inner face, the stretch of the elastic member when the curved portion of the wire harness is warped is prevented so that the curved portion can be smoothly warped in directions of reducing or increasing the diameter of the curve. Thus, the looseness of the wire harness can be absorbed smoothly and surely.
In a preferred embodiment, the elastic member includes a first spring segment along a curved outer face of the wire harness and a second spring segment along a curved inner face of the wire harness, the second spring segment protrudes toward a free end of the elastic member and the spring segment has a spring constant larger than that of the first spring segment.
In this configuration, the curved portion of the wire harness is drawn up by the outer first spring segment and is pushed up by the inner second spring segment. Thus, the looseness of the wire harness when the sliding structure is opened/closed can be surely absorbed. Particularly, since the second spring segment on the tip side has a small spring constant, the curved portion of the wire harness can be greatly reduced in diameter against the spring force by small force. This suppresses the force required to open or close the sliding structure, thereby improving the operability of opening/closing. Further, since the curved portion of the wire harness can be reduced in diameter when the sliding structure is fully opened, the curved portion of the wire harness when the sliding structure is fully opened can be set at a small diameter. This contributes to decrease the size of the power supply structure. For example, the protector for accommodating the sliding structure can be downsized. This enhances freedom of arrangement or design of components in the sliding structure to which the protector is attached.
Preferably, the first spring segment and the second spring segment are coupled by a coupling segment. In such a configuration, the elastic member can be easily formed at low cost. Further, since the coupling segment can be used to position the wire harness in a radial direction, the assembling of the wire harness with the elastic member can be facilitated.
Preferably, a tip segment and a stem segment of the second spring segment protrude from the coupling segment in opposite directions, and the stem segment of the second spring segment is opposed to the first spring segment. In this configuration, the tip side of the second spring segment and the stem side thereof are individually located before and after the coupling segment, the wire harness can be held stably. Since the stem side of the second spring segment is opposed to the first spring segment, the urging force can be increased, thereby permitting the looseness to be surely absorbed.
Preferably, the first spring segment, the second spring segment and the coupling segment are formed in a sheet form, and the second spring segment is shorter and narrower than the first spring segment. In such a configuration, the power supply structure can be made compact. Since the wire harness is supported additionally at the free end of the elastic member in such a configuration, the curved portion of the wire harness can be greatly reduced in diameter by small force. This contributes to downsize the power supply structure.
Preferably, the wire harness is fixedly sandwiched between the first spring segment and the spring segment at the coupling segment. This configuration facilitates the operation of securing the elastic member to the wire harness, improves the operability of assembling and reducing the production cost since another securing member is not required.
In a preferred embodiment, the elastic member is bent at an intermediate position in a longitudinal direction to form a bending segment and arranged a curved outer face of the wire harness, a tip of the elastic member is secured to the wire harness, and the bending segment is separated from the wire harness.
In such a configuration, when the wire harness is pulled so that its curved portion is reduced in diameter as the sliding structure is opened/closed, the elastic member is warped to bend at its intermediate bending portion. Therefore, the curved portion of the wire harness can be reduced in diameter so that the operation of opening/closing the sliding structure can be smoothly carried out and the curved portion can be greatly reduced in diameter by smaller force (than using a straight elastic member) Thus, the power supply structure inclusive of the protector can be downsized.
Particularly, the tip of the elastic member is secured to the wire harness and the intermediate portion of the elastic member is separated from the wire harness so that a gap is formed between itself and the wire harness. For this reason, the wire harness can be easily bent at a small curvature of radius so as to fill the gap. Thus, the curved portion of the wire harness can be reduced in diameter by small force.
In a preferred embodiment, the elastic member is composed of a flat spring segment in contact with a curved inner face of the wire harness and a spiral segment the center of which is fixed.
In such a configuration, the flat spring segment pushes up the wire harness in a curved shape and the spiral segment as well as the flat spring reduces the elastic member itself in diameter. Specifically, the combined function of the flat spring segment and the spiral segment reduces the curved portion of the wire harness in diameter by small force so that the sliding structure can be smoothly opened or closed by small force and the power supply structure inclusive of the protector corresponding to the curved portion can be downsized.
Particularly, since the flat spring segment curves along the spiral segment to constitute a part of the spiral segment, the elastic member can be reduced in diameter so that the curved portion of the wire harness can be reduced in diameter and the power supply structure can be miniaturized. Since the flat spring segment in contact with the inner curved face of the wire harness urges the curved portion in a pushing-up direction, it is not necessary to secure the elastic member to the wire harness. Unnecessity of the operation of securing reduces the production cost.
Preferably, the elastic member is provided with a harness supporting member at its tip.
In this configuration, when the wire harness expands/contracts in opening/closing the sliding structure, because of the harness supporting member, interference between the edge or tip of the elastic member and the wire harness or the corrugated tube with unevenness can be prevented. This permits the wire harness to expand or contract smoothly and its looseness to be absorbed.
Preferably, wherein the harness supporting member is thicker at least at its tip than the elastic member. In this configuration, interference between the edge or tip of the elastic member and the wire harness or the corrugated tube with unevenness can be prevented more surely.
Preferably, a curved portion of the wire harness and the elastic member are housed in a protector.
In this configuration, the curved portion of the wire harness and the elastic member can be protected from external interference and the wire harness is curved along the curved shape of the protector so that its initial shape is defined as a curved portion. This permits the operation of reducing or enlarging the diameter of the curved portion to be smoothly carried out and the looseness of the wire harness can surely be absorbed.
Preferably, the elastic member is secured to the protector at its stem.
In this configuration, when the stem of the elastic member is secured to the protector, the elastic member is cantilever-supported. Therefore, the urging force of lifting the wire harness can be surely exhibited. In addition, the protector and elastic member are integrated to provide a unit of the power supply structure.
Preferably, the stem has a first recess, the protector has an inserting portion corresponding to the stem, and the elastic member is secured to the inserting portion by a securing jig engaged with the recess.
In this configuration, since the elastic member is firmly secured to the inserting portion with the recess of the elastic member secured by the securing jig, even when strong pulling force is acted on the elastic member through the wire harness (in a direction of removing the elastic member) in closing/opening the sliding structure, the removal of the elastic member can be surely prevented. Thus, the urging of the wire harness by the elastic member (absorption of the looseness of the wire harness) can be carried out precisely so that the wire harness can be provided from being caught in between the sliding structure and the body. Further, since elastic member is firmly secured to the protector by the securing jig, it is not necessary to secure the elastic member to the stem of the wire harness by tape winding or band winding. Therefore, the troublesome operation of securing the wire harness having a sectional circular and elliptical shape along the elastic member in a sheet form is not required, thereby improving the operability of assembling. This effect can be further enhanced by the structure in which the securing jig is secured to the protector by securing means. Preferably, the inserting portion has a second recess having a shape similar to that of the first recess. Therefore, the securing jig can be simultaneously engaged with the first recess of the elastic member and the second jig of the inserting portion. This increases the securing force (force of preventing removal) of the elastic member. Therefore, the above effect can be further enhance, and the securing structure is simplified and its production cost can be reduced.
Preferably, the securing jig has elastic force enough to nip the inserting portion. In this case, the elastic member is inserted in the inserting portion and the inserting portion is nipped externally by the securing jig so that the elastic member can be secured to the inserting portion. This makes it unnecessary to use the securing means. This contributes to downsizing the sliding structure and saving the space thereof. This also simplifies the operation of assembling to improve the workability.
The above and other objects and features of the invention will be more apparent from the following description taken in conjunction with the accompanying drawings.